In an image forming apparatus, a memory storing data such as characteristics of each toner cartridge is provided for the toner cartridge, and control of transfer, fixing or the like is performed based on the data.
In the image forming apparatus as stated above, when a power source is turned on, or a new toner cartridge is mounted to the image forming apparatus, it is determined that there is a possibility that the toner cartridge is replaced. All data is read from a memory on a toner cartridge side, and is read into a memory on an image forming apparatus side. For example, at the time of return from a sleep mode for energy saving, or at an opening and closing of a toner cartridge, reading of all data is similarly performed.
At this time, respective components of the image forming apparatus are also started, and the data is read before completion of start-up of, for example, a fixing unit including a heat source which takes a relatively long time to start.
In a color printer of an image forming apparatus, since data is sequentially read from memories of respective toner cartridges of yellow, magenta, cyan and black, a readout time is four times longer than that of a monochrome printer. Although it is conceivable to reduce data content in order to shorten the data readout time, the reduction of the data content itself is difficult.